Track for impact: Conservancy of Southwest Florida studies invasive pythons’ movements

Andrea Stetson

After eight years of sloshing through murky water, climbing trees and crawling through brush to wrestle giant Burmese pythons, Ian Bartoszek and his team have published their findings in a national magazine.

Bartoszek, the Conservancy of Southwest Florida’s environmental science project manager, his team of wildlife biologists, in partnership the United States Geological Survey, published research in the June issue of Ecosphere on the longest and largest tracking study on the invasive Burmese python.

More:Summer events from the Marco Island Historical Society

“We are just breaking cover and coming out to share information,” Bartoszek said. “This is just a paper looking through a wide angle lens of what these adult pythons are doing on the landscape.”

The report shows the results of research gathered as they tracked 25 of the 84 pythons, they have been following via radio transmitters set beneath the skin of these invasive reptiles. The report coincides with the Conservancy team recently reaching a milestone of capturing 20,000 pounds of Burmese pythons in the 100 square miles that they are monitoring.

Scientists say that understanding the spatial ecology of an invasive species is critical for designing effective control programs. Discovering their estimated home range and habitat can streamline targeted removal efforts.  The study began eight years ago with a python named Elvis. After being captured, the giant reptile was sent to work as a spy. Tracking him led biologists to nesting females, other males and python eggs.  Burmese pythons typically lead a cryptic life, hiding in very rural, off the main path areas. That has made capturing them extremely difficult.

“You need this background information if you are attempting to create strategies against them,” Bartoszek explained. “We have few tools in the toolbox to find and remove them. This is the longest and largest study on Burmese pythons around. That can help guide management strategies. That is valuable intel on where they are moving, what habitats they are choosing and how much space they are choosing in southwestern Florida.”

One of the most important findings is how to best plan a capture.

“We know during breeding season they are selecting upland features,” Bartoszek said. “Those are areas that can be searched more during breeding season.”

This year spy pythons they named Loki and Ender were the top agents leading them to remote areas where they were able to capture numerous pythons.

More:‘Wynne’s Warriors’: MIA's Key Club raise funds to help 3-year-old with rare disease

“Loki – he led us to some really big females, across canals and over crappy habitat,” Bartoszek described. “We got a 148 pound female and a couple of males. That was the easy part. The hard part was getting them back to the lab. The scouts take us off grid, sometimes it is by roads or levies, but lots of time they are deep in the wild.”

About 75 percent of the 20,000 pounds of pythons caught during the study are females. That not only takes those creatures out of the wild, but it prevents them from laying eggs and growing the population.

“I feel like this is a good start for us, “Bartoszek said. “But every time I get in the car and drive through the Everglades, I get disheartened. It is a vast area. We work on one area and we see another area gaining ground. It is a little frustrating.”

 At the lab the pythons are either put down humanely or outfitted with a transmitter and sent off to work as a spy.

The study, conducted on public conservation lands in Rookery Bay National Estuarine Research Reserve, Collier Seminole State Park, Picayune Strand State Forest, and on adjacent private lands, taught scientists that males have a home range of about 2.6 square miles, while female’s home range is 1.1 square miles.

Kristen Hart, a research ecologist with USGS, is also an author on the publication. She said the sharing of information and collaboration between the Conservancy and USGS has helped tremendously.

“They have really done such heavy lifting,” Hart explained. “Our strength is the analysis part. We made sense of what did all the location data mean.”

The numbers are clearly showing Hart and other researchers how to best manage this invasive species.

“I think there are clearly areas that are the high upland areas that the females are utilizing,” Hart said. “When and where pythons are in an egg laying state, those areas can definitely be searched out and prioritized.”

Studies from the University of Florida identified 24 species of mammals, 44 species of birds and two reptile species have been found inside pythons.

“Every time we do a necropsy, most snakes over 12 feet have the remains of white tail deer,” Bartoszek added. “We feel like we are playing CSI crime scene in the lab.”

That illustrates how pythons are taking meals away from native predators, causing significant declines in wildlife populations and putting pressure on the ecosystem.

The work is exhausting and often treacherous. Recently the team was called to capture a 15.5 foot female that was 12 feet up in a tree hanging over the water. Bartoszek climbed the tree while his partner waited below to grab the creature when it dropped.

“It feels like a tour of duty each season. It does feel like special forces operations here,” Bartoszek said.

Most times the reptile captured is more than a mile from their truck. The men learned that carrying the creature on their shoulders is easier than in a bag.

“We donated a lot of blood and sweat on this project,” Bartoszek said. “It is very physical, very mental. It is a very stressful assignment. It is hard earned. We want to stay at it because we know what is at stake here.”

Hart agrees. “In this battle to figure our pythons, we are all trying to figure out their biology and their removal,” Hart said.

The Burmese python is a large, nonvenomous constrictor snake that was introduced in Southwest Florida at the end of the 1990’s. It is originally from Southeast Asia. Bartoszek believes the problem began from intentional releases, escapes and natural disasters such as Hurricane Andrew in 1992 that knocked over reptile places causing the creatures to escape to the wild.

“It is kind of like a virus that is spreading, and there are multiple inoculation sites,” Bartoszek said.

The report does not signal the end of the study. That will continue indefinitely.

For Hart and the USGS the next step is adding accelerometers, very high activity sensors, to the pythons.

“It is like the technology in a Wii,” Hart explained.

The new technology will allow scientists to collect more intricate data.

“It is collecting data at once a second in three dimensions,” Hart described. “We are hopeful we can tell if they are feeding or if they are striking. It takes consistent, persistent work on these animals to really figure them out. It is a really long term relationship.”

The Conservancy is also continuing their study.

“We are going to follow the science on this issue and see where it takes us,” Bartoszek said. “We will follow the science so it can inform land managers and decision makers to follow this important issue of our time”.

He hopes one day the study will give scientists an estimate on how many Burmese pythons might be in the wild. Bartoszek stressed that native snakes are good for the environment. He also stressed that people should not be afraid of the Burmese pythons. They do not hunt humans. They only go after their prey.

More:Police: Marco Island man arrested for stalking after leaving vulgar note on woman's car

“I am more afraid of driving my field truck around during season than wrangling snakes,” he said. “We have a lot of respect for this animal. They are pretty magnificent creatures. They didn’t do anything wrong. They escaped from the pet trade. We know we will never get them all.”

While Bartoszek admits the job is stressful, tiring and tough, he loves his work, and plans to continue with it as long as he can.

“I am a wildlife biologist and to have the ability to track and learn an animal’s behavior that is still unknown, it’s a novelty today,” he said. “It seems like everything today is figured out. This is a new assignment. Every season we see something new. We are not in it for the bounty, we are not in it for the money, we are in it because we have identified it is important. Where else can you wrestle an apex species into a bag and then go out and do it again? It really challenges you. It is really logistic. We are on the adventure.”


To report an invasive species sighting, the public is asked to call 1-888-IVE-GOT1 or report via the “IveGot1” mobile app. For more information, visit


  • Burmese pythons can grow up to 20 feet in length in the wild
  • The average size in Florida is 8-10 feet
  • They are native to Southeastern Asia
  • They are active during the day in cool months
  • They are seen on the roads at night when it is warm
  • Females lay 12-95 eggs each year In southwestern Florida the average size is 42 eggs.
  • In Florida they cannot be acquired as personal pets
  • *Source  The Conservancy of Southwest Florida and FWC